Dental handpiece



Dec. 8, 1931. o. H. PIEPER 1,835,961

DENTAL HANDPIECE Filed April 17, 1930 2 SheetsSheet l a I %zIsA TTOR NE Y 0. H. PIEPER DENTAL HANDPIECE Filed April '17, 1930 Dec; 8, 1931.

2 Sheets sheet 2 "v? v fi INVENTOR V LN 8 QV Nm MG M A TTORNEV Patented Dec. 8, 1931 OSCAR H. PIEPER. or noonn'srnn, new YORK j ENT-AL Hammer.

Application filed April 17,

licient in service, convenient 'to operate, and

one in which the parts can be quickly and easily assembled to afford a complete instrument. e 1

A further o'bj ect of the invention is to provide in an instrument of this type improved tool driving means together with improvements in the control and operating parts therefor, along with other improvements which eiiect economies in manufacture, and which insure a practical and simplified construction.

To these and other endsthe invention resides in certainimprovements and combina' tions of parts, all as will be hereafter more fully disclosed, the novel features being pointed out in the claims at the end of the A specification.

Inthe drawings: 7 Fi 1 is a side view illustrating one embodiment of the invention; f Fig. 2 is. a view showing the spindle and operating parts from which the casing has been removed; I

Fig. 3 is a longitudinal central section throughthe instrument, drawn to an enlarged scale and showing theparts in normal operating position; I

Fig. 4% is a similar view with the parts moved to position to effect release of the chuck;

Fig. 5 is a longitudinal section through the supporting head and spindle With the chuck and control parts therefor removed; Fig. 6 is a detail View of the plunger and associated. parts for controlling the clutchoperating means;

Fig. '7 is an enlarged fragmentary section through the end of the instrument carrylng thedriving pulley and showing the relationship of the various parts thereof;

Fig. 8 is an enlarged transverse section taken on line 8a-.8a of Fig. 3; r 0 Fig. 9 :is an enlarged transverse sectio takenon-the -line.9a19a of Fig. 3, and

193,0. Serial No. 444,894.

Fig. 10 is a detail perspective view of'one of the operating parts formovingthe chuck to'closed position. v f

Similar reference numerals throughout the several viewsindicate the's'ame' arts,- 5

The present invention embodies a dental instrument of the class generally known as e a dental hand piece'in whi-chthere are various operating-and control parts for the'di'ffer-f ent drilling, cutting, and' ipolishin g tool seiri-l ployed in various'operations on the teeth. "In the presentembodiment ofthe invention, improvements have "been made relating to variousparts'ofthe construction, such as an improved and positive drive for the tool,

along with means by'which proper ad -just:

ment between different operating parts may be readily eflectedyandother improvements, certain of which facilitate assembling and detachment of anumber ofthe elements ;go- 7 ingto make up'the completeinstrument.- o

Referring to the drawingslO represents the usual wr ist joint frame or head piece,

a projecting sleeve '11. fitted within therear end of the body of a casing comprising the front and rear'secti'on's 12 and 12a, theflatter being in the form of a coupling flanged atl3 for engagement iby a hollownut, 14 secured upon the head and connecting the coupling therewithg""Threaded Within the, coupling 'is a member 13a havingnotches 1400 for receiving afsui'table tool to be employed I for rotating said member to v'ary-ltheeffective length of the casing for a purpos'e which will appear hereinafter, it 'beingimderstood that said member forms a stop for the cats ing section 12 when the latter is screwed intothe coupling. Threaded ithinthe frame 10 is a bearing member 15 forming a continuation of the casing in which is journaled the reduced end portion'ilfi o'f ahollow spindle 17, said spindle"having a shou'lder l7a"aliutting a spacing member 1.8a ontheend-of thefbearing member, thedatterprojecting within the sleeve 11 of the head piece. At: the tool fholding end of the instrument the casing is provided'with a tapered bearing portion 18 in' 'which *is ournaled the eerie-'- spondingly' tapered portio'nll9 ofthejt'ool car-f ryingendofthespindle. The frame 10 and the casing with its bearings afford a rigid support or mounting for the spindle and permit the latter to freely rotate therein. The rear end of the spindle is extended through the bearing member 15 and is preferably reduced at at which point it receives the oppositely disposed bearing sleeves 21 and 22 of the spindle driving pulley 23, secured to said reduced portion by a clamping screw 24, the sleeve portion 22 being slightly spaced from the bearing member 15 'to'permit of a limited movement of the spindle within the bearing member. The reduced portion 20 is slotted at 25 to receive the inner end of a driving pin 26 inserted'within a bore formed in the wall of the pulley, the pin being preferably anchored by forcing it into the bore under considerable pressure. By loosening the clamping screw 24 the pulley may be adj usted longitudinally of the spindle whendesired'without having to remove the driving pm. i.

3 The bearingl5'is ram with a knurled head27 by which it may be rotated to adjust it to the desired position within the head 10, the bearing being held in adjusted position preferably by a set screw 28. Thehead 27 is recessed to receive the sleeve portion 22 of the pulley, which rotates therein, said sleeve portion being surrounded by a ring 29 of felt or other suitable material positioned Within the head and which is saturated with oil or other suitable lubricating material, whereby to properly lubricate the bearing and the spindle therein.

Disposed within the forward end portion 19 of the spindle is a suitable tool clamping device 30, 1 which preferably comprises a sjpringfjawed chuck of a well known type,

the extremities of the jaws being beveled for .cooperation'at one end with a beveled bearing portion 31 of the spindle permanently fixed thereon and at'theopposite end for cooperation with the beveled portion 32 of a follower or chuck closing member 33 slidably mounted within the bore of the spindle. The shank of the tool or cutting implement 34 is gripped and held by the jaws of the chuck when the follower 33 is forced outwardly to the position shown in Fig. 3. The follower is provided with a socket or recessed portion 34 arranged to receive the inner end of the tool shank, the latter being beveled at 35 to facilitate its entrance within the socket. In

order to afiord a positive driving connection between the follower and the tool, the latter is provided with an abutment 36 arranged to receive a driving lug or abutment 37 on the follower, preferably in the form of a stud suitably anchored within the surrounding wall of the recess 34a. The abutment 36 is preferably formed by providing a flattened portion on the inner end of the tool. at one side thereof. Longitudinal movement of the tool inwardly of the spindle is limited chuck is merely that of holding the tool against: displacement, the chuck being relieved of the tendency of the tool to shift longitudinally therein under the pressure exerted on the operating end of the tool while in service which is taken by the shoulder 38 in engagement with the lug 37. v

Rotation of the follower with the spindleis effected by a driving element 39 extending through the rear endofthe follower and hav-' ing. its end portions projecting into the longitudinally extending slots '40 and 41 formed in opposite sides of the spindle fora portion of its length. The wall portions at the opposite sides of the slots form abutmen'ts for engaging the ends of the driving element, so

that the follower and spindle always operate together; "The driving element is detachably' held within the follower by a pin" slidably mounted withinthe end of the follower and extending through the driving element, the pin having a head 43 between which and the follower are disposed one or more shim-s or spacing elements 44 provided fora purpose which will appear hereinafter.

- An actuating member formoving the follower outwardly within the spindle to close the chuck 'preferably comprises a lever 45 mountedto swing within the spindle. The actuating element has a transverseend portion 46 for engagement with the head 43 of thefollower, said portion having laterally extending trunnion-like members 47 which are rounded at one side and positioned within bearings 48 formed in the side walls of the slot 40 in the spindle. The longitudinally extending part of the lever lies opposite and is free to move within the slot 41 to the operating and release positions indicated respectively in Figs. 3 and 4.. I

The shims 44 interposed between the body of the follower and the head 43 of the pin provide for a ver'y'fine adjustment of the effective length of the follower in order that it may have the exact amount ofumovement required to properly close the clutch, while at the same time preventing undue movement of the lever. Furthermore, the thickness or number of the shims can be varied from time to time to compensate for the wear of the parts, so that the adjustment may be properly maintained under all conditions of operation.

The operating means for the lever is of unitary construction and embodies a plunger plunger beingslotted at 50 to receive the longitudinally extendingportion'of the lever. Thepllunger on its forward end is provided with ;a'eam or inclined portion 51 adapted when the plunger move-s outwardly to the position shownin Fig. 3 to engage the free end of the lever, whereby to operate the lever for the purpose :of moving the follower to chuck closing position; The plunger is held in the normal operating position shown in F i g. 3 by means of a {spring 52,;one end of which engages the head or .thum b piece .53 to which the plunger is suitablyconnected. The other end of the spring engages the pulley which is fixed to thehollow spindle so that the spring tends to constantly urge the follower in a direction away from the tool holding end of the instrument. In order to effect release of the tool holdingchuck, it is only necessaryto depress the plunger to the position shown in Fig. 4, in which position the tool may be readily withdrawn from the chuck and another inserted therein qif desired. Upon release of the thumb ,piece 53, the spring will immediately return the plunger to the .normal operating position shown in Fig. 3, thus causing the cam 51 to swing the lever into position to force the follower into engagement with the jaws of the chuck. The thumb piece 53 is provided with a sleeve 54: cooperating with-a similar member on the pulley to conceal the spring in whatver position the-plunger may occupy within the spindle. The inward movement of the plunger is preferably limited by engagement of the sleeve 5a with the pulley when the are in-jthe position shown in Fig. 4.

Guard means is provided for limiting the outward novementof the plunger when applying the leverAS which is done before the spindle is insertedwithin the casing. This means preferably comprises a leaf spring 56 raving one end suitably secured to vZthe plunger, ,as by means of a rivet 57, and the opposite end provided with a lug or holding part 58 arranged to engage a shoulder or abutment 59 on the spindle when the plunger is freeto move outwardlyiunder the action-of. By limiting the outward the spring 52. movement ofthe plunger in this manner it is held against undue displacement within the spindle by the action of. the spring when inserting or removing the lever from the spindle and also whenapplying or. removing the detachable parts associated with the rear end of the follower. On the-other hand the plunger and its cam 51 may be readily withdrawn together with .the guard 56 byfirst'depressing the latter by means of a suitable tool inserted through the slot 40 to release said guard. Furthermore, on inserting the plunger within the spindle and" moving it inwardly the guard will .be automatically depressed through engagementof the beveled portion 60 thereof with the end of the spin-- dle andasksoon as the lug-8 of the spring reaches theslot 4C0 itwill spring into the lat' ter, as shown in Fig. 3. It-will be seen, there ter, together with the chuck, can be 'easilydischarged through the rear-end of the spindle with which thepulley is connected. By providing for the insertionandpremoval of the parts in this manner [the assembling and repair. operations are greatly facilitated and the expense incident to the time consumed and thelabor .costsare considerably reduced. It will be understoodthat the lever, the driving element 39, the pin 43', and the shims 44 will be applied before inserting the spindle within the casing. The casing is preferably provided witha detachable sleeve61 of fluted construction to afford a suitable hand grip for the instrument, the. same being. :held aga-inst'outw ard movement'by a set screw '62 threaded within the bearing portion 18 of the casing.- g

Thefront bearing' 31 of the spindle on which the forward end o-fthe chuck rests is positively fixed with respect to the body of the spindle and the chuck therefore will al ways occupy the same position within the spindle, thus insuring .proper relationship between the chuck: and the remaining tool operating parts. Thepi-vot bearings 48 of the lever are also fixed with relation to thef-ront bearing of the chuck and the lever therefor .hasa fixed position with respect to thechuclr. -.An y adjustment which may becomenecessary by reason .of slight variations in the. dimensions of these parts either when new or after they have become wornmay be readily compensated for by varying the thickness'or'number of the shimsa ll-disposed' between thefollower and the head of the .pin

therein on which the lever rests. 4

The object in making the detachablesleeves in two sectionsis to permit its efiective. .length to be varied when desired. In. supplying these instruments to thedental no w profession severalextra sleeves-may be:fur-* nished wi'th each complete instrument. in

order to permit ,of frequent sterilizing of these i-parts'which form-the hand grips by which the instruments are held. 7 It will be understood "that while the instrument ,with' one hand grip is in use'theother handgrips these parts-may vary slightly in length; It. is important, however,- :tlhait they should be;

accurately fitted to the spindle bearings and the dentist or other operator'using the instrument can in applying the'sleeve to the spindle, readily tell whetheror not it is properly adjusted for length. If it is found that the sleeve is slightly too long or too short the correct adjustment may be effected by the use of a suitable tool employed to rotate the member 13a either to move it inwardly or outwardly as the conditions may require. By then screwing the section 12 within the coupling 12a until it abuts said member the adjustment is completed and the casing may then be applied by inserting it in position and securing the same to the head by screwing up the nutl. In doing this the forward bearing 18 of the sleeve due to the thrust on the spindle, will cause the latter to become properly positioned with respect to the bearing member15 so that longitudinal movement of the spindle within the casing is prevented; Y I

The driving belt for the pulley 23, not shown, is carried around a pair ofguide pulleys 63, only one of which is shown. The pulleys 63 are mounted on a head 64: pivotally connected'w'ith the outer end of an arm 65 having-a reduced portion journa-led in a sleeve bearing 66 secured upon and extend ing from the frame 10, Fig. 1, the head being also connected with an arm section 67 sup portedby a well known form of construction, not shown.

I claim: f

'1; A'dental hand piece comprising a support, a spindle mounted for rotatio-nwithin the support, a tool holding chuck in the forward end of the spindle, a follower within the spindle for closing the chuck arranged to be drivenby the spindle, the follower having an abutment fixed thereon and independ ent of the spindle arranged for engagement with an butment on the rear end of the tool whereby to positively drive the tool upon rotation of the follower, and operating 7 means for moving the follower longitudinally withinthe spindle to chuck closing position.

r 2. A dental hand piece comprising a casing, a "spindle mounted. for rotation within the casing, a tool mounted within oneend of the spindle, a clamping device for the tool disposed within said spindle end, a memberlocated within the spindle arranged to be driven thereby and movable to a predetermined position to urge the clamping device in engagement with the tool, said member having a part independent of the spindle arranged to engage and positively drive the tool, and spring actuated operating means for sai'd'member serving to holdit in said predetermined position.

3; A dental hand piece comprising a cas ing, a spindle mounted for rotation within the casing, a chuck mounted 'within one end of the spindle, a tool extending through the chuck, a follower mounted within the spindle arranged to be driven thereby and to be moved into position to cause the chuck to grip the tool, said follower having a receiving portion for the inner end of thetool provided with an offsetdriving member independent of the spindle and constructed to engage and positively drive the tool upon rotation of'the spindle and relatively movable parts associated withthe spindle for holding the follower in said position. a V Y 4. A dental hand piece comprising a casing, a spindlejmounted for rotation within the casing, a chuck in one end of the spindle for holding a tool' to be inserted within the chuck with its opposite ends projecting therefrom, a follower arranged to be driven by and movable longitudinally within the spindle to close the chuck, said follower having a recess therein for receiving the inner end of the tool and having a part thereon independent of the spindle arranged for cooperationwith an abutment formedon said inner end whereby to positively drive the tool, relatively movable operatingparts for the follower and spring means for moving said parts to move the follower to chuck closing position.

5. A dental hand piece comprising a sup port, a spindle mounted for rotation within the support, a tool holding chuck in the forward end'of the spindle, a follower within the spindle for closing the chuck arranged to be driven by the spindle, the follower having its forward end recessed in rear of the chuck to receive the rear end of a tool having thereon a shoulder and anabutment, a lug on the follower mounted independentlyof the spindie and projecting into the recess arranged to r be engaged by the shoulder of the tool to limit inward movement of the-latter,the lug cooperating with the abutment on the tool whereby to positively drive the tool upon rotation of the follower, and operating means for moving the follower longitudinally with-' in the spindle to chuck closing position.

6. A dental hand piece comprising a casing, a spindle mounted for rotation within the casing and provided with an abutment, a tool holding chuck within one end of the spindle, a follower for closing the chuck movable withinth'e spindle and comprising relatively movable-parts, one of which is slidable longitudinally of the other, one or more spaced members interposed between said parts to effect a variation in the length of'the follower, a driving element for the follower projecting'laterally therefrom into engagement with the abutment and movable with the follower upon the abutment and relative to the spindle and means including relatively movable parts within the'casing for moving the follower to chuck closing position.

7. A dental hand piece comprising a casing, a hollow spindle mounted for rotation within the casing and havinga recess in its wall,- a tool holding chuck disposed within one end of the spindle, a follower for operating the chuck movable within the spindle and comprising relatively movable parts one of which includes a portion slidably mounted within the other part and having a head,

thereon, one or more spaced. members interposed between said head andthe part in which said portion is mounted whereby to vary the'eiiective length of the follower, driving" means for the follower projecting therefrom into said recess and movable with the followerlongitudinally of the spindle, an op erating member for thefollower extending within the spindle arranged to engage said head and to movethe follower to chuck closing position, and releasable means for holding the operating member in position to urge the follower in engagement with the chuck.

8. A'dental hand piece comprising a cas-' ing,- aspindle mounted for rotation with-in the casing, a tool holding chuck disposed within one end of the spindle, a follower for closing the chuck slidably mounted within the spindle and comprising inner and outer parts movable one relative to another, a driv ingjm'ember for the follower secured upon one of said parts by the other, said driving member extending into'e'ngagementwith the spindle, follower movable within 'the spindle to close the chuck, a driving element for the follower projecting therefrom into engagement with said abutment whereby upon rotation of the spindle said element will operate to drive the follower, an operating member within the bore of the spindle'for effecting longitudinal movement of the fol lower therein, and a plunger within the spindle'proje'cting' from the rear end thereof arranged to; move said operating member to e-ffect'movem'ent of the follower.

10. A dental hand piececompri'sing a casing,a spindle mounted for rotation within the casing and having an abutment formed thereon, a tool holding chuck disposed within one end of the spindle, a fol'lowerslidably" mounted within the spindle to engage and close the chuck, a driving element for the fol lower mounted within a recess' formed therein and projecting laterally therefrom into engagement with said abutment for operation thereby,saidid'riving-elementhaving an opening therein, a securing member for said element disposed within a recessed portion ofi thefollow'e'r andprojecting intoth'e opening of the driving elementto secure the latter. I

upon the follower, an operating member for the follower having a partarranged to en: gage said securing member to actuate the latter whereby to move the followerto chuck closing position and actuating means for the operating member; 1

1 1. A dental hand piece of the spindle, operating means for the chuck disposed within the spindle, a plunger within v the rear end of the spindle for actuating said means, and a spring actuated guard within the spindle arranged for cooperation-there with to hold the plun er against removal, therefrom, said guardlieingi'movable to a position within the spindle at which it will free the plunger for removal throughthe: rear 7 l l 12. A dental hand piece comprising a.sup-" port, a hollow spindle j'ournaled in the' supend of .the' spindle.

port, a tool holding chuck in the forward end omprising Port, a hollow spindle journaled' in the support, a tool holding chuck in theforward end of the spindle, operating means for the chuck disposedwithin the spindleya plunger within.

the rear end of the spindle for actuating. said means, a spring within the spindlesecured: to the plunger and movable therewith, said" spring having a part projecting into'a slotv formed: within the spindle and arranged in a; predetermined position-of the plunger-to (20 V operate with the spindle whereby to'hold the plunger againstremoval therefromf, said: spring'bei-n'g movableto a position to permit withdrawal of the plunger from tllG SPlI-ldlfi: 7 l3.- A dental hand piece comprising a support, a hollow spindle journaled in the sup-' port, a tool holding chucki-n' the forward end of the spindle, actuating. means for the chuck including relatively movable parts within:

the spindle and a plunger within the spindle j having a portion for operating oneof said parts, the-plunger and said portion being. free" to slide within the, spindle during operation of said actuating means and removable as a unit through the rear'end of the spindle.

14; A dental hand piece comprising a sup port, a hollow spindle journaled in-the sup-. port, a tool holding chuck in the forward end of the spindle, a follower within the spindle for closing the chuck, an operating element for the follower movable relative thereto, a plunger in the rear end of the spindle having an actuating part thereon for said operating element, said plunger and said follower and chuck being removable through the rear end" of the spindleand: spring means for holding.

the plunger in position to maintainthe actuating part in operative engagement with the fol-lower operating element.-

a 15. A dental hand piece comprising a sup=- port, ahollow spindle rotatably mounted within the support, a tool holding chuck intheforward end of the spindle, operating means within the spindle for closing the" chuck, a plunger within the rearend ofth'e. spindle for actuating'said operating means,

and an adjustable guard interposed between the spindle and plunger arranged when the plunger is in a predetermined position with in the spindle to check outward movement of the plunger, said guard being releasable to permit its withdrawal together with the plunger as a unit'through the rear end of the spindle.

16. A dental hand piece comprising a support, a casing having one end connected to the support, and the other spaced therefrom, a hollow spindle having its forward end journaled in the last mentioned end of the casranged when the plunger is moved in a direc r tion away from the follower to a predetermined position to swing said actuating element into operative engagement with said follower, said plunger and operating part being removable as a unit from'the rear end of the spindle, and spring means normally operating to hold the plunger in said predetermined position, movement of the plunger from said position in the direction of the follower serving to release the actuating element. r

g V 17 A dental handpiece comprising a head, a hollow spindle having one end journaled in the head, an operating ineinberfor the spindle connected therewith, a casing for the spindle in which the forward'end of the latter is.]ournaled, said casing comprising connected sections ad1ustable one longitudinally of the other to vary the eifective length of the casing, means deta-chably connecting the casing with the head, a tool holding chuck within the spindle, a chuck closing device movable within the spindle, operating means for said chuck closing device comprising a lever pivoted within the spindle, a plunger within the spindle removable through the rear end thereof, yieldable means normally serving to hold the plunger in position to maintain the lever in operative engagement withthe chuck closing device and a guard for holding the plunger against removal from the spindle. I

18. A dental hand piece comprising a head, a bearing supported by the head, a hollow spindle projecting throughthe head journaled' in the bearing and held thereby against rearward longitudinal 'inovement a casing for the spindle havinga bearing therefor serving tohold the spindle against forward movement longitudinally of the casing, said casing comprising connected sections ad ustable one longitudinally of the other, a member threadedly engaging one of said sections andforming an abutment for engagement by one extremity of the other section whereby to regulate theeifective length of the cas ng by varying the spacing of the said bearings,

means detachably connecting the, casing with the head, a tool holding chuck within the spin-,

dle, operating means for the chuck movable within the spindle including a plunger pro jecting through the rear end of the spindle and means yieldably holding the plunger in normal operating position.

19. A dental hand piece comprising a sup-o,

port, a casing having one end connected to the support and the other spaced therefrom,

a hollow spindle having its forward end means for said actuating member comprising a plunger mounted within the rear end of the spindle and having an operatingpart arranged when the plunger is inoved in a direction away from the follower to a predetermined position to swing said actuating element into operative engagement with said follower and a releasable guard on the plunger arranged to cooperate with a portion of the spindle to limit movement of the plunger in a direction away from the follower.

20. A dental hand piece comprisinga head, a casing connected with the head, a hollow spindle within the casing having its forward end journaled in the front end of the casing and its rear end extending through and journaled in the head, a driving member connected with the spindle in rear of the-head, a'tool holdingchuck in the forward end of the spindle,a follower for operating the chuck located within the spindle, a lever within the spindle for operating the follower, a plunger within a the spindle having its forward end operative- 1y engaging the lever and its rear end projecting through the head and the driving member on the spindle, said plunger including the lever engaging portion thereof being constructed for removal as a unit through the rear end of the spindle, and yieldable means serving to hold the plunger in oper ative engagement with the lever.

21. A dental hand piece comprising a head, a casingconnected with the head, a hollow spindle within the casing having'its forward end journaled in the front end of the casing and its rear end extending through and journaled in the head, 'a driving member's-conin i1) nected with the spindle in rear of the head, a tool holding chuck in the forward end of the spindle, a follower for operating the chuck located within the spindle, a lever within the spindle for operating the follower, a plunger within the spindle having its forward end operatively engaging the lever and its rear end projecting through the head and the driving member on the spindle, said plunger including the lever engaging portion thereof being constructed for removal as a unit through the rear end of the spindle, an adjustable guard on the plunger arranged in normal position to cooperate with the spindle to prevent withdrawal of the plunger, said guard in another position being removable with the plunger as a unit from the spindle, and yieldable means serving to hold the plunger in operative engagement with the lever.

OSCAR H. PIEPER. 

